Mystery of the Proton

[luke warm]

I am not sure what the speed of thought is, I think our electical brain impulses do not move faster than light but if you mean I think of a place and go there that would be faster.

that's exactly what i mean... it gets a little metaphysical... for example, we know there isn't a material or physical link between thought and distance (or at least we think we do), but when there are esteemed scientists who disagree over things like light speed, etc, it tends to show to me that we (mankind) don't know as much as we like to pretend we do

 

I always thought the problem is crossing the light speed barrier, in other words something can go faster than the speed of light or slower but crossing the barrier is the problem. We get heavier and too fat to cross over, takes more energy than exists.

that's what i've always thought, also... but who knows? some say quasars more faster, and if that's true then the 'problem' isn't insurmountable

 

Alternatively, try showing that a swallow can fly faster than the speed of light

doesn't have to be a swallow, eh? did you read the article(s)?

[helene_t]

I don't think the special relativity theory is being challenged.

 

But it's quite possible for a perceived object to travel faster than light as long as it doesn't carry information. After all, how do we know that perceived objects are real? I saw a storry a few days ago about sound that travels faster than light. Just akin to this well-known thought experiment:

 

Take two narrow sticks and place one on top of the other, with a tiny angle between them. Now move them appart with a speed of 299.000.000 meter per second. The point of intersection between the two sticks now travels faster than light. Not really interesting.

[whereagles]

There are many examples of things that go faster than light:

 

Phase velocity in wave packets

Cherenkov radiation

Tachyonic particles

Virtual velocities

Globally defined quantum wave functions

 

but none of these violate the principle that information cannot propagate faster than the speed of light in the vacuum.

[mike777]

There are many examples of things that go faster than light:

 

Phase velocity in wave packets

Cherenkov radiation

Tachyonic particles

Virtual velocities

Globally defined quantum wave functions

 

but none of these violate the principle that information cannot propagate faster than the speed of light in the vacuum.

This is because the speed of light, c, is less in a medium than the speed of light which is a constant c in a vacuum? For instance the speed of light is only .75c in water?

[helene_t]

No, the things that Whereagles refers to actually exceed the speed of light in vacuum, they just don't carry information.

 

Think of the speed of your mouse coursor on the screen. If your screen is one million kilometers wide, and the mose cursor is in one corner now and in the opposite corner one second later, the mouse cursor has traveled faster than light. The reason why this is possible is, of course, that the mouse cursor is an illusion: the pixels on your screen do not travel at all, they just change color.

 

In quantum mechanics, the identity of a particle is a delicate matter: when you look at the waves that propagate across the sea it looks as if the waves are entities that move but actually the water molecules do not move with them (as you can convince yourself by dropping some dye in the water).

 

So you might ask: are the waves on the water illusions (like the mouse cursor) and, therefore, not necesarily forbidden of traveling faster than light? Or are they "real" and therefore forbidden to travel faster than light? Because of the wave/particle duality you can ask the same question about particles as well.

 

The way to answer the question is to see if the entity in question is able to carry information. Surface waves can carry information and therefore cannot travel faster than light. Mouse cursors cannot carry information.

 

What does it mean to carry information? A letter carries information because the sender can make some decision (such as whether to write "Dear Bob" or "Dearest Bob") which has consequences for an event that happens at the receiving end (whether the reader reads "Dear Bob" or "Dearest Bob"). The same is true for surface waves: if the waves travel from your place to mine, you can chose either to distort the wave or not to, and we can agree that a distorted wave is a message that means something. You can't do the same with the mouse cursor.

[luke warm]

does (assume that the first article i posted is a fact, ie the speed of light has indeed changed or is changing) the speed of light matter? iow, say this speed dropped to 185,000 miles/sec... would that mean that information that could conceivably have been passed at 185,500 miles/sec would now be uable to do so?

[helene_t]

Not sure if I understand your question, Jimmy, but no, the speed of light doesn't matter. If you hold some information that you received yesterday at 300.000.000 m/s express mail and today the speed of light is only 299.000.000 m/s, you can still trust that information.

[luke warm]

that's pretty much what i was asking, helene... if no information can move faster than the speed of light in a vacuum, it doesn't matter what the speed is... whether or not light speed has slowed, the theory holds...